System on chip controlling memory power using handshake process and operating method thereof

ABSTRACT

A system on chip (SoC) adjusts power of a memory through a handshake. The SoC includes a memory controller and a power manager. The memory controller is configured to control a memory. The power manager is configured to manage a supply power level of the memory. The memory controller is configured to output, to the power manager, a memory access level indicating a frequency of accesses to the memory. The power manager is configured to adjust the supply power level of the memory according to the memory access level.

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. non-provisional patent application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2017-0009371, filed on Jan. 19, 2017 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates to a system on chip (SoC) and a method of operating the same. More particularly, the present disclosure relates to an SoC that controls power of a memory through a handshake.

2. Description of the Related Art

An SoC is a semiconductor technology by which an existing complex system having various functions is embodied as a single chip. The SoC may include a device with a unique circuit arrangement (e.g., a specific circuit arrangement protected by intellectual property rights), and a memory. The device with the unique circuit arrangement may be a device that functions as a master that accesses the memory to process data, etc.

Also, the SoC may include a power manager that manages power of the memory, or the like. In the SoC, the power manager may provide a uniform level of supply power to the memory, such that it is necessary to efficiently manage power so that operation performance of the memory does not degrade.

SUMMARY

The present disclosure provides a SoC including a power manager capable of reducing power consumed by a memory by optimizing power consumption thereof.

The present disclosure provides a method of operating a power manager capable of reducing power consumed by a memory by optimizing power consumption thereof.

According to an aspect of the present disclosure, an SoC includes a memory controller and a power manager. The memory controller is configured to control a memory. The power manager is configured to manage a supply power level of the memory. The memory controller is configured to output, to the power manager, a memory access level indicating a frequency of accesses to the memory. The power manager is configured to adjust the supply power level of the memory according to the memory access level.

According to another aspect of the present disclosure, a method of operating a power manager included in an SoC includes receiving a memory access level indicating a frequency of accesses to a memory from a memory controller. The method also includes determining whether the memory access level is equal to or higher than an access level threshold. The method further includes outputting a control signal for setting a supply power level of the memory.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a block diagram of a SoC, according to an embodiment;

FIG. 2 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 3 illustrates a flowchart of an operation of a power manager, according to an embodiment;

FIG. 4 is a graph illustrating a relationship between a supply power level and a memory access level, according to an embodiment;

FIG. 5 illustrates a flowchart of a method of operating an SoC, according to an embodiment;

FIG. 6 illustrates a flowchart of a method of operating an SoC, according to an embodiment;

FIG. 7 illustrates a flowchart of a method of operating an SoC, according to an embodiment;

FIG. 8 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 9 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 10 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 11 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 12 illustrates a timing diagram of a memory power transition interval of an SoC, according to an embodiment;

FIG. 13 illustrates a block diagram of a memory system, according to an embodiment;

FIG. 14 illustrates a block diagram of an SoC, according to an embodiment;

FIG. 15 illustrates a block diagram of an SoC, according to an embodiment; and

FIG. 16 illustrates a block diagram of an example of a semiconductor system including an SoC, according to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 illustrates a block diagram of a SoC 10 according to an embodiment.

As described herein, a SoC 10 may be a single, integrated circuit provided as a single chip such that all components are physically connected directly or indirectly to one another on a single substrate. The SoC 10 may be a device that is installed as a component in another device. The SoC 10 may include communications capabilities such as for digital and/or analog signals. The SoC 10 may include all components of, for example, an electronic system or sub-system.

Referring to FIG. 1, the SoC 10 may include a first voltage domain 11, a second voltage domain 12, and a power manager 400. The first voltage domain 11 may include first to N^(th) masters 100_1 to 100_N, a memory controller 200, and a memory 300. The second voltage domain 12 may also include first to M^(th) masters (unnumbered), an additional memory controller (unnumbered), and an additional memory (unnumbered). Different power voltages may be applied to the first voltage domain 11 and the second voltage domain 12. For example, a first power voltage may be applied to the first voltage domain 11, and a second power voltage may be applied to the second voltage domain 12. FIG. 1 illustrates two voltage domains, i.e., the first voltage domain 11 and the second voltage domain 12, but the voltage domains are not limited thereto. The SoC may include only one voltage domain, or more than two voltage domains.

FIG. 1 illustrates that the first voltage domain 11 includes the first to N^(th) masters 100_1 to 100_N, the memory controller 200, and the memory 300, and the second voltage domain 12 includes the additional first to M^(th) masters (unnumbered), the additional memory controller (unnumbered), and the additional memory (unnumbered). However, at least some of the first to N^(th) masters 100_1 to 100_N, the memory controller 200, and the memory 300 may be shared among the voltage domains, i.e., the first voltage domain 11 and the second voltage domain 12. That is, the first voltage domain 11 and the second voltage domain 12 may share the same N^(th) masters 100_1 to 100_N, the same memory controller 200, and/or the memory 300 in common. Similarly, the first voltage domain 11 and the second voltage domain 12 may also, or alternatively, share the additional first to M^(th) masters (unnumbered), the additional memory controller (unnumbered), and the additional memory (unnumbered). Hereinafter, only the first voltage domain 11 and the elements therein will be described, but the descriptions thereof may be applied to the second voltage domain 12 and the additional unnumbered elements shown therein in FIG. 1.

The first to N^(th) masters 100_1 to 100_N may indicate (e.g., correspond to) all intelligent devices that may access the memory 300 through the memory controller 200. The first to N^(th) masters 100_1 to 100_N may access the memory 300. To this end, the first to N^(th) masters 100_1 to 100_N may be connected to the memory controller 200 for communication therebetween. For example, the first to N^(th) masters 100_1 to 100_N may read data from the memory 300 by outputting an address to the memory controller 200 or may write data to the memory 300 by outputting the data to the memory controller 200.

The memory controller 200 may output various signals for controlling the memory 300. The memory controller 200 may read data from the memory 300 by outputting an address thereto or may write data to the memory 300 by outputting the data thereto.

The memory controller 200 may include an access level managing unit (ALMU) 210. The ALMU 210 may generate information regarding a frequency of accesses (i.e., number of accesses over a specified time) of the first to N^(th) masters 100_1 to 100_N to the memory 300. Hereinafter, in the present specification, a memory access level may indicate a frequency of accesses of the first to N^(th) masters 100_1 to 100_N to the memory 300. For example, the ALMU 210 may identify and provide, as the memory access level, a count of each read request and each write request made by the first to N^(th) masters 100_1 to 100_N to the memory 300 during a unit time. According to an embodiment, the ALMU 210 may output the generated memory access level to the power manager 400. The frequency of accesses may correspond to the number of accesses over a specified fixed unit time, such as over a second, minute, hour, day, or year. Alternatively, the frequency of accesses may correspond to the number of accesses between particular events, such as an event that starts a clock and the current time.

The memory 300 may be a semiconductor device that may write or read data and may be a memory that may quickly write or read data. The memory 300 may be a volatile memory such as a Static Random Access Memory (SRAM), a Dynamic RAM (DRAM), a latch, a Flip-Flop, or a register. However, the memory 300 is not limited thereto, and the memory 300 may be a non-volatile memory such as a NAND Flash Memory, a Vertical NAND (VNAND), a NOR Flash Memory, a Resistive RAM (RRAM), a Phase Change RAM (PRAM), a Magnetoresistive RAM (MRAM), a Ferroelectric RAM (FRAM), or a Spin-Transfer Torque RAM (STT-RAM). The memory 300 may perform a write operation by receiving data and an address from the memory controller 200 or may perform a read operation by receiving an address.

The power manager 400 may manage power supplied to the memory 300. The power manager 400 may be embodied as a power management unit (PMU) on the SoC 10. A power management unit may be or include a microcontroller, and may include firmware, software stored in a dedicated memory, and a processor that executes the software to perform processes of a power manager 400 as described herein. The power manager 400 may include a power adjustment unit 410, defined as a combination of power adjustment software stored in the dedicated memory and the processor that executes the power adjustment software. The power adjustment unit 410 may adjust a supply power level of power supplied to the memory 300. The supply power level is changed from a current supply power level to a new supply power level.

According to an embodiment, the power manager 400 may receive the memory access level from the memory controller 200 and may determine the supply power level of the memory 300. Also, the power manager 400 may output, to the memory controller 200, a result of determining the supply power level of the memory 300. A “handshake” as described herein, may generally refer to processes whereby (1) the memory controller 200 outputs the memory access level to the power manager 400, the power manager 400 (2) determines the supply power level of the memory 300 based on the memory access level, and the (3) the power manager 400 outputs a determination result to the memory controller 200. According to the present disclosure, since the memory controller 200 and the power manager 400 may identify the memory access level and the supply power level of the memory 300 and thus may adjust the supply power level accordingly, power of the memory 300 may be effectively managed. The supply power level is changed from the current supply power level to the new supply power level based on the memory access level, and thus based on the frequency of access to the memory 300.

According to an embodiment, the memory controller 200 of the first voltage domain 11, the memory controller of the second voltage domain 12, and the power manager 400 may each adjust the supply power level of the power supplied to the memory 300 through a handshake. Since reference voltages of the first voltage domain 11 and the second voltage domain 12 are different from each other, different levels of power may be applied to the memory 300 even though the first voltage domain 11 and the second voltage domain 12 have the same memory access level.

FIG. 2 illustrates a block diagram of the SoC 10 according to an embodiment, and the corresponding descriptions provided with reference to FIG. 1 will not be repeated.

Referring to FIG. 2, the SoC 10 may include the memory controller 200, the memory 300, and the power manager 400. The memory controller 200 may include the ALMU 210. The memory 300 may include a power switching unit 310. The power manager 400 may include the power adjustment unit 410 and an adjustment determination unit 420.

The ALMU 210 may output a memory access level MAL to the adjustment determination unit 420 based on accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N of FIG. 1). The adjustment determination unit 420 may compare the memory access level MAL with at least one preset access level threshold and may output a determination result DR to the power adjustment unit 410. The determination result DR may include two or more states, depending on the number of access level thresholds. For example, when there is one access level threshold, the adjustment determination unit 420 may output a busy state Busy to the power adjustment unit 410 as the determination result DR if the memory access level MAL is higher than a first access level threshold. The adjustment determination unit 420 may output an idle state IDLE to the power adjustment unit 410 as the determination result DR if the memory access level MAL is lower than the first access level threshold.

The power adjustment unit 410 may receive the determination result DR and may output, to the power switching unit 310, a supply power control signal Ctrl_SP that differs depending on the determination result DR. For example, when receiving the busy state Busy as the determination result DR, the power adjustment unit 410 may output the supply power control signal Ctrl_SP for adjusting the supply power level to a first supply power level. When receiving the idle state IDLE as the determination result DR, the power adjustment unit 410 may output the supply power control signal Ctrl_SP for adjusting the supply power level to a second supply power level. In this case, the first supply power level may be higher than the second supply power level.

Based on the supply power control signal Ctrl_SP, the power switching unit 310 may adjust power supplied to the memory 300. To this end, the power switching unit 310 may include at least one switching device (e.g., a Metal Oxide Semiconductor (MOS) transistor) connected to a power source. For example, the power switching unit 310 may include a transistor including a gate, and the supply power control signal Ctrl_SP may be transmitted to the gate so as to control ON/OFF states of the transistor; thereby, a level of the power supplied to the memory 300 may be adjusted.

FIG. 3 illustrates a flowchart of an operation of the power manager 400 according to an embodiment.

Referring to FIGS. 2 and 3, in operation S110, the adjustment determination unit 420 may receive the memory access level MAL from the ALMU 210. The adjustment determination unit 420 may compare the received memory access level MAL with the access level threshold.

When the memory access level MAL is determined to be higher than the access level threshold in operation S120, the power adjustment unit 410 may output the supply power control signal Ctrl_SP and may set the supply power level of the memory 300 as the first supply power level in operation S130. When the memory access level MAL is determined to be lower than the access level threshold in operation S120, the power adjustment unit 410 may output the supply power control signal Ctrl_SP and may set the supply power level of the memory 300 as the second supply power level in operation S140. According to an embodiment, the first supply power level may be higher than the second supply power level. That is, the power adjustment unit 410 may be configured to perform a process that includes setting the supply power level.

As in operations S110, S120, and S130 of FIG. 3, when the memory access level MAL is higher than the access level threshold, an operation of the power manager 400 is referred to as a first route A, and detailed descriptions thereof are provided with reference to FIG. 5. As in operations S110, S120, and S140 of FIG. 3, when the memory access level MAL is lower than the access level threshold, an operation of the power manager 400 is referred to as a second route B, and detailed descriptions thereof are provided with reference to FIGS. 6 and 7.

FIG. 4 illustrates a graph showing a relationship between a supply power level SPL and a memory access level MAL, according to an embodiment. In detail, FIG. 4 illustrates an embodiment in which there are two access level thresholds, that is, a first access level threshold ALT1 and a second access level threshold ALT2.

Referring to FIGS. 2 and 4, the adjustment determination unit 420 may receive the memory access level MAL from the ALMU 210. The memory access level MAL may have consecutive values. The adjustment determination unit 420 may compare the received memory access level MAL with the first access level threshold ALT1 and the second access level threshold ALT2.

When the memory access level MAL is lower than the first access level threshold ALT1, the adjustment determination unit 420 may output the idle state IDLE to the power adjustment unit 410 as the determination result DR. Then, the power adjustment unit 410 may output a supply power control signal Ctrl_SP corresponding to a first supply power level SPL1 to the power switching unit 310. In response to the supply power control signal Ctrl_SP, the power switching unit 310 may adjust the power supplied to the memory 300 to be at the first supply power level SPL1.

When the memory access level MAL is higher than the first access level threshold ALT1 but lower than the second access level threshold ALT2, the adjustment determination unit 420 may output a normal state Normal to the power adjustment unit 410 as the determination result DR. Then, the power adjustment unit 410 may output the supply power control signal Ctrl_SP to the power switching unit 310, wherein the supply power control signal Ctrl_SP corresponds to a second supply power level SPL2 higher than the first supply power level SPL1. In response to the supply power control signal Ctrl_SP, the power switching unit 310 may adjust the power supplied to the memory 300 to be at the second supply power level SPL2.

When the memory access level MAL is higher than the second access level threshold ALT2, the adjustment determination unit 420 may output the busy state Busy to the power adjustment unit 410 as the determination result DR. Then, the power adjustment unit 410 may output the supply power control signal Ctrl_SP to the power switching unit 310, wherein the supply power control signal Ctrl_SP corresponds to a third supply power level SPL3 higher than the second supply power level SPL2. In response to the supply power control signal Ctrl_SP, the power switching unit 310 may adjust the power supplied to the memory 300 to be at the third supply power level SPL3.

FIG. 4 illustrates an embodiment in which there are two access level thresholds. However, there may be one access level threshold or at least three access level thresholds.

FIG. 5 illustrates a flowchart of a method of operating the SoC 10, according to an embodiment. In detail, FIG. 5 is a flowchart of a method of operating the SoC 10 with regard to the first route A of FIG. 3. That is, the method of operating the SoC 10, in which the memory access level MAL is higher than the access level threshold, will be described.

Referring to FIGS. 2, 3, and 5, operation T110 is performed in which the memory controller 200 may output the memory access level MAL to the power manager 400. In operation T120, the power manager 400 may determine the memory access level MAL by using the method described with reference to FIGS. 2 to 4. When it is determined that the memory access level MAL is higher than the access level threshold, operation T130 may be performed in which the power manager 400 may output, to the memory 300, the supply power control signal Ctrl_SP for increasing the supply power level to the first supply power level. In operation T140, the memory 300 may selectively output, to the power manager 400, a signal indicating that an increase of the supply power level is completed. The signal indicating that an increase of the supply power level is completed may be a power increase completion signal. When the increase of the supply power level of the memory 300 is completed, operation T150 may be performed in which the power manager 400 may output, to the memory controller 200, the signal indicating that the increase of the supply power level is completed. In response to the signal, the memory controller 200 may allow masters to access the memory 300 in operation T160. Then, in operation T170, the memory controller 200 may selectively output, to the power manager 400, a signal indicating that the access to the memory 300 has been allowed. Operations, e.g., operations T140 and T170, which are indicated by dashed lines, may be selectively performed.

FIG. 6 illustrates a flowchart of a method of operating the SoC 10, according to an embodiment. In detail, FIG. 6 is a flowchart of another method of operating the SoC 10 with regard to the second route B of FIG. 3.

Referring to FIGS. 2, 3, and 6, operation T210 is performed in which the memory controller 200 may output the memory access level MAL to the power manager 400. In operation T220, the power manager 400 may determine the memory access level MAL by using the method described with reference to FIGS. 2 to 4. When it is determined that the memory access level MAL is lower than the access level threshold, operation T230 may be performed in which the power manager 400 may output, to memory controller 200, a signal for decreasing necessary power. The necessary power may be required to perform operations regarding the memory 300.

In operation T240, the memory controller 200 may decrease the necessary power for the memory 300 in response to the above signal. A method, by which the memory controller 200 decreases the necessary power for the memory 300, will be described in detail with reference to FIGS. 8 to 10. After the decrease of the necessary power for the memory 300 has been completed, operation T250 may be performed in which the memory controller 200 may output an acknowledgement signal Ack to the power manager 400.

In response to the acknowledgement signal Ack, operation T260 is performed in which the power manager 400 may output, to the memory 300, the supply power control signal Ctrl_SP for decreasing the supply power level to the second supply power level. In operation T270, the memory 300 may selectively output, to the power manager 400, a signal indicating the completion of the decrease of the supply power level. An operation, e.g., operation T270, which is indicated by a dashed line, may be selectively performed.

FIG. 7 illustrates a flowchart of a method of operating the SoC 10, according to an embodiment. In detail, FIG. 7 is a flowchart of another method of operating the SoC 10 with regard to the second route B of FIG. 3.

Referring to FIGS. 2, 3, and 7, operation T310 is performed in which the memory controller 200 may output the memory access level MAL to the power manager 400. In operation T320, the power manager 400 may determine the memory access level MAL by using the method described with reference to FIGS. 2 to 4. When it is determined that the memory access level MAL is lower than the access level threshold, operation T330 is performed in which the power manager 400 may output, to memory controller 200, a signal for decreasing necessary power. A preset period of processing time passes in operation T340. Then operation T350 is performed in which the power manager 400 may output, to the memory 300, the supply power control signal Ctrl_SP for decreasing the supply power level to the second supply power level in response to the signal for decreasing the necessary power. The processing time in operation T340 may be a time necessary for the memory controller 200 to decrease the power necessary for the memory 300. For example, the processing time may be a time necessary to perform operation T240 of FIG. 6. In operation T360, the memory 300 may selectively output, to the power manager 400, a signal indicating the completion of the decrease of the supply power level. An operation, e.g., operation T360, which is indicated by a dashed line, may be selectively performed.

FIG. 8 illustrates a block diagram of an SoC 10 a according to an embodiment. In detail, FIG. 8 is a block diagram of a method of operating the SoC 10 a with regard to the second route B of FIG. 3. That is, a method of operating the SoC 10 a, in which a memory access level MAL is lower than an access level threshold, will be described.

Referring to FIGS. 6 and 8, the SoC 10 a may include a memory controller 200 a and a power manager 400 a. The memory controller 200 a may include an ALMU 210 a and a delaying unit 220 a. The power manager 400 a may include a power adjustment unit 410 a and an adjustment determination unit 420 a.

When detecting accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N) to a memory (e.g., the memory 300 of FIG. 2), the ALMU 210 a may generate a memory access level MAL. The ALMU 210 a may output the generated memory access level MAL to the adjustment determination unit 420 a. The adjustment determination unit 420 a may output, to the power adjustment unit 410 a, the determination result DR (e.g., the idle state IDLE of FIG. 4) indicating that the memory access level MAL is lower than the access level threshold.

In response to the determination result DR, the power adjustment unit 410 a may output a necessary power decrease request signal RPD to the delaying unit 220 a, as in operation T230 of FIG. 6. In response to the necessary power decrease request signal RPD, the delaying unit 220 a may delay a response Rsp corresponding to the accesses Acc of the masters and may output the response Rsp. The masters may receive the response Rsp from the memory controller 200 a and then may request to access the memory. Thus, when the delaying unit 220 a delays and outputs the response Rsp regarding the masters, access frequencies of the masters may decrease. Accordingly, the necessary power for the memory may decrease. After the necessary power decreases due to the delayed response Rsp, the delaying unit 220 a may output an acknowledgement signal Ack to the power adjustment unit 410 a. After receiving the acknowledgement signal Ack, the power adjustment unit 410 a may adjust the power supplied to the memory to be at a low level.

FIG. 9 illustrates a block diagram of an SoC 10 b according to an embodiment. In detail, FIG. 9 is a block diagram of a method of operating the SoC 10 b with regard to the second route B of FIG. 3. That is, the method of operating the SoC 10 b, in which the memory access level MAL is less than the access level threshold, will be described.

Referring to FIGS. 6 and 9, the SoC 10 b may include a memory controller 200 b and a power manager 400 b. The memory controller 200 b may include an ALMU 210 b, a delaying unit 220 b, and an access queue 230 b. The power manager 400 b may include a power adjustment unit 410 b and an adjustment determination unit 420 b.

When detecting accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N) to a memory (e.g., the memory 300 of FIG. 2), the ALMU 210 b may generate the memory access level MAL. The ALMU 210 b may output the generated memory access level MAL to the adjustment determination unit 420 b. The adjustment determination unit 420 b may output, to the power adjustment unit 410 b, the determination result DR (e.g., the idle state IDLE of FIG. 4) indicating that the memory access level MAL is less than the access level threshold.

In response to the determination result DR, the power adjustment unit 410 b may output a necessary power decrease request signal RPD to the delaying unit 220 b, as in operation T230 of FIG. 6. In response to the necessary power decrease request signal RPD, the delaying unit 220 b may store, in the access queue 230 b, access information AInfo regarding the accesses Acc of the masters, unlike the embodiment of FIG. 8. As the memory controller 200 b stores the access information AInfo in the access queue 230 b instead of immediately performing, on the memory, an operation corresponding to the accesses Acc, the necessary power for the memory may be reduced. Operations according to the stored access information AInfo may be sequentially performed later. After the necessary power is reduced due to an operation regarding the response Rsp, the delaying unit 220 b may output an acknowledgement signal Ack to the power adjustment unit 410 b. After receiving the acknowledgement signal Ack, the power adjustment unit 410 b may adjust the power supplied to the memory to be at a low level.

FIG. 10 illustrates a block diagram of an SoC 10 c according to an embodiment. In detail, FIG. 10 is a block diagram of a method of operating the SoC 10 c with regard to the second route B of FIG. 3. That is, the method of operating the SoC 10 c, in which a memory access level MAL is lower than an access level threshold, will be described.

Referring to FIGS. 6 and 10, the SoC 10 c may include a memory controller 200 c and a power manager 400 c. The memory controller 200 c may include an ALMU 210 c and a blocking unit 240 c. The power manager 400 c may include a power adjustment unit 410 c and an adjustment determination unit 420 c.

When detecting accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N) to a memory (e.g., the memory 300 of FIG. 2), the ALMU 210 c may generate a memory access level MAL. The ALMU 210 c may output the generated memory access level MAL to the adjustment determination unit 420 c. The adjustment determination unit 420 c may output, to the power adjustment unit 410 c, the determination result DR (e.g., the idle state IDLE of FIG. 4) indicating that the memory access level MAL is lower than the access level threshold.

In response to the determination result DR, the power adjustment unit 410 c may output a necessary power decrease request signal RPD to the blocking unit 240 c as in operation T230 of FIG. 6. In response to the necessary power decrease request signal RPD, the blocking unit 240 c may output a fail signal Fail to the masters. When the blocking unit 240 c outputs the fail signal Fail in response to the accesses Acc of the masters, the masters may request to access the memory again. Accordingly, access frequencies of the masters may decrease. Thus, the necessary power for the memory may decrease. After the necessary power for the memory decreases due to a blocking operation, the blocking unit 240 c may output an acknowledgement signal Ack to the power adjustment unit 410 c. After receiving the acknowledgement signal Ack, the power adjustment unit 410 c may adjust the power supplied to the memory to be at a low level.

FIG. 11 illustrates a block diagram of an SoC 10 d according to an embodiment, and corresponding descriptions provided with reference to FIG. 2 will not be repeated.

Referring to FIG. 11, the SoC 10 d may include a memory controller 200 d and a power manager 400 d. The memory controller 200 d may include an ALMU 210 d, a transition unit 250 d, and a latch unit 260 d. The power manager 400 d may include a power adjustment unit 410 d and an adjustment determination unit 420 d.

When detecting accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N) to a memory (e.g., the memory 300 of FIG. 2), the ALMU 210 d may generate a memory access level MAL. The ALMU 210 d may output the generated memory access level MAL to the adjustment determination unit 420 d. The adjustment determination unit 420 d may compare the memory access level MAL with an access level threshold and may output the determination result DR to the power adjustment unit 410 d.

The power adjustment unit 410 d may output a power adjustment signal PA to the transition unit 250 d before outputting a supply power control signal (e.g., the supply power control signal Ctrl_SP of FIG. 2) regarding the memory. The power adjustment signal PA may include information indicating that power supplied to the memory is adjusted by the power adjustment unit 410 d. That is, by outputting the power adjustment signal PA to the transition unit 250 d, the power adjustment unit 410 d may notify the transition unit 250 d that the power supplied to the memory is adjusted. In response to the power adjustment signal PA, the transition unit 250 d may output a clock inactivation signal CD to the latch unit 260 d. In response to the clock inactivation signal CD, the latch unit 260 d may inactivate a received clock Clk.

FIG. 12 illustrates a timing diagram of a memory power transition interval T_PT of an SoC, according to an embodiment.

Referring to FIGS. 11 and 12, before outputting a supply power control signal (e.g., the supply power control signal Ctrl_SP of FIG. 2) regarding the memory, the power adjustment unit 410 d may output the power adjustment signal PA to the transition unit 250 d. In response to the power adjustment signal PA, the transition unit 250 d may output the clock inactivation signal CD to the latch unit 260 d. In response to the clock inactivation signal CD, the latch unit 260 d may inactivate a clock Ck during the memory power transition interval T_PT in which a level of memory supply power MP changes.

Since the level of the memory supply power MP changes in the memory power transition interval T_PT, a problem may occur with regard to reliability of received data DATA. Thus, the transition unit 250 d may inactivate the clock Ck so that the latch unit 260 d may not receive data DATA during the memory power transition interval T_PT. After the memory power transition interval T_PT ends, the power adjustment unit 410 d may stop outputting the power adjustment signal PA. In response to a halt of the output, the transition unit 250 d may stop outputting the clock inactivation signal CD to the latch unit 260 d. Accordingly, the latch unit 260 d may activate the clock Ck again after the memory power transition interval T_PT and may receive the data DATA again.

FIG. 13 illustrates a block diagram of a memory system 1 e according to an embodiment, and the corresponding descriptions provided with reference to FIG. 2 will not be repeated.

Referring to FIG. 13, the memory system 1 e may include an SoC 10 e and a power source 20 e. The SoC 10 e may include a memory controller 200 e, a memory 300 e, and a power manager 400 e. The SoC 10 e may be substantially the same as or similar to the SoC 10 of FIG. 2 except in respect of a power adjustment unit 420 e that outputs the supply power control signal Ctrl_SP to the power source 20 e instead of the memory 300 e. The power source 20 e is configured to supply power to the memory 300 e.

The power adjustment unit 420 e may generate the supply power control signal Ctrl_SP based on the determination result DR received from an adjustment determination unit 410 e and may output the generated supply power control signal Ctrl_SP to the power source 20 e. The power source 20 e may provide the SoC 10 e with supply power SP having at least one level. For example, the power source 20 e may be embodied as a Power Management Integrated Circuit (PMIC). In response to the supply power control signal Ctrl_SP, the power source 20 e may adjust a level of the supply power SP supplied to the memory 300 e. When the supply power control signal Ctrl_SP is a signal for adjusting the supply power SP to have a first supply power level, the power source 20 e may adjust the supply power SP supplied to the memory 300 e to have the first supply power level. When the supply power control signal Ctrl_SP is a signal for adjusting the supply power SP to have a second supply power level, the power source 20 e may adjust the supply power SP supplied to the memory 300 e to have the second supply power level.

FIG. 14 illustrates a block diagram of an SoC 10 f according to an embodiment, and the corresponding descriptions provided with reference to FIG. 2 will not be repeated.

Referring to FIG. 14, the SoC 10 f may include a memory controller 200 f and a power manager 400 f. The memory controller 200 f may include an ALMU 210 f and an adjustment determination unit 270 f. The power manager 400 f may include a power adjustment unit 410 f. The SoC 10 f may be substantially the same as or similar to the SoC 10 of FIG. 2 except in respect of the adjustment determination unit 270 f included in the memory controller 200 f.

The ALMU 210 f may detect accesses Acc of masters (e.g., the first to N^(th) masters 100_1 to 100_N) to a memory and may generate a memory access level MAL. The ALMU 210 f may output the memory access level MAL to the adjustment determination unit 270 f included in the memory controller 200 f. To this end, the adjustment determination unit 270 f may be included in each voltage domain (e.g., the first voltage domain 11 and second voltage domain 12 of FIG. 1). The adjustment determination unit 270 f may compare the memory access level MAL with access level thresholds (e.g., the first access level threshold ALT1 and the second access level threshold ALT2) and may output the determination result DR to the power adjustment unit 410 f included in the power manager 400 f.

FIG. 15 illustrates a block diagram of an SoC 10 g according to an embodiment, and the corresponding descriptions provided with reference to FIG. 2 will not be repeated.

Referring to FIG. 15, the SoC 10 g may include a memory controller 200 g and a power manager 400 g. The memory controller 200 g may include an ALMU 210 g. The power manager 400 g may include a power adjustment unit 410 g, an adjustment determination unit 420 g, and an access level threshold (ALT) storage unit 430 g. The ALMU 210 g, the power adjustment unit 410 g, and the adjustment determination unit 420 g may be substantially the same as or similar to the ALMU 210, the power adjustment unit 410, and the adjustment determination unit 420 of FIG. 2, respectively.

The ALT storage unit 430 g may store an access level threshold ALT. To this end, the ALT storage unit 430 g may include a volatile memory such as an SRAM, a DRAM, a latch, a Flip-Flop, or a register, or a non-volatile memory such as a NAND Flash Memory, a VNAND, a NOR Flash Memory, an RRAM, a PRAM, an MRAM, an FRAM, or an STT-RAM.

The ALT storage unit 430 g may output the access level threshold ALT to the adjustment determination unit 420 g. The adjustment determination unit 420 g may compare the access level threshold ALT with a memory access level MAL and may output the determination result DR to the power adjustment unit 410 g. In an embodiment, the ALT storage unit 430 g may store at least one access level threshold ALT. For example, the ALT storage unit 430 g may store a first access level threshold and a second access level threshold and may output the first access level threshold and the second access level threshold to the adjustment determination unit 420 g. The adjustment determination unit 420 g may compare the memory access level MAL with both the first access level threshold and the second access level threshold and may output different determination results DR to the power adjustment unit 410 g.

In an embodiment, the ALT storage unit 430 g may receive an access level threshold ALT′ that is changed by a host, etc. The ALT storage unit 430 g may store the changed access level threshold ALT′ and may output the stored access level threshold ALT′ to the adjustment determination unit 420 g. In response to the output, the adjustment determination unit 420 g may generate the determination result DR by comparing the access level threshold ALT′ with the memory access level MAL and may output the determination result DR to the power adjustment unit 410 g.

FIG. 16 illustrates a block diagram of an example of a semiconductor system 900 including an SoC, according to an embodiment.

Referring to FIG. 16, the semiconductor system 900 may include an Application Processor (AP) 901, an antenna 910, a radio frequency (RF) transceiver 920, an input device 930, and a display 940. The AP 901 may be a Modem AP (ModAP) having a modem function. According to an embodiment, the AP 901 may include any SoC described with reference to FIGS. 1 to 15. In other words, the AP 901 may adjust power supplied to the memory, according to a frequency of accesses to the memory included in the AP 901. The frequency of accesses may correspond to the number of accesses over a specified fixed time period, such as over a second, minute, hour, day, or year. Alternatively, the frequency of accesses may correspond to the number of accesses between particular events, such as an event that starts a clock and the current time.

The RF transceiver 920 may exchange wireless signals with an external device via the antenna 910. For example, the RF transceiver 920 may convert the wireless signals, which are exchanged via the antenna 910, into signals that may be processed by the AP 901. Therefore, the AP 901 may process signals output from the RF transceiver 920 and may transmit the processed signals to the display 940.

Also, the RF transceiver 920 may convert signals, which are output from the AP 901, into wireless signals and may output the wireless signals to an external device via the antenna 910. The input device 930 may be a device used to input control signals for controlling an operation of the AP 901 or data to be processed by the AP 901. The input device 930 may be embodied as a keypad, a keyboard, or a pointing device such as a touch pad or a computer mouse.

The descriptions herein refer to a variety of units, controllers and managers. Any of these units, controllers and managers may be embodied by a processor that executes a particular dedicated set of software instructions, such as a software module. The processor executes the instructions to control operations of the units, controllers and managers. Multiple of the units, controllers and managers may be defined by a single common processor and different dedicated sets of software instructions. Any processor of a unit, controller or manager described herein is tangible and non-transitory. As used herein, the term “non-transitory” is to be interpreted not as an eternal characteristic of a state, but as a characteristic of a state that will last for a period of time. The term “non-transitory” specifically disavows fleeting characteristics such as characteristics of a particular carrier wave or signal or other forms that exist only transitorily in any place at any time. A processor is an article of manufacture and/or a machine component. A processor is configured to execute software instructions in order to perform functions as described in the various embodiments herein. A processor may be a general-purpose processor or may be part of an application specific integrated circuit (ASIC). A processor may also be a microprocessor, a microcomputer, a processor chip, a controller, a microcontroller, a digital signal processor (DSP), a state machine, or a programmable logic device. A processor may also be a logical circuit, including a programmable gate array (PGA) such as a field programmable gate array (FPGA), or another type of circuit that includes discrete gate and/or transistor logic. A processor may be a central processing unit (CPU), a graphics processing unit (GPU), or both. Additionally, any processor described herein may include multiple processors, parallel processors, or both. Multiple processors may be included in, or coupled to, a single device or multiple devices. Sets of instructions can be read from a computer-readable medium. Further, the instructions, when executed by a processor, can be used to perform one or more of the methods and processes as described herein. In a particular embodiment, the instructions may reside completely, or at least partially, within a main memory, a static memory, and/or within a processor during execution.

In an alternative embodiment, dedicated hardware implementations, such as application-specific integrated circuits (ASICs), programmable logic arrays and other hardware components, can be constructed to implement one or more of the methods described herein. One or more embodiments described herein may implement functions using two or more specific interconnected hardware modules or devices with related control and data signals that can be communicated between and through the modules. Accordingly, the present disclosure encompasses software, firmware, and hardware implementations. Nothing in the present application should be interpreted as being implemented or implementable solely with software and not hardware such as a tangible non-transitory processor and/or memory.

While the inventive concepts of the present disclosure have been particularly shown and described with reference to embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the following claims. 

What is claimed is:
 1. A system on chip (SoC), comprising: a memory controller configured to control a memory; and a power manager configured to manage a supply power level of the memory, wherein the memory controller is configured to output, to the power manager, a memory access level indicating a frequency of accesses to the memory, and the power manager is configured to adjust the supply power level of the memory according to the memory access level.
 2. The system on chip of claim 1, wherein the power manager is further configured to output, to the memory controller, a result of adjusting the supply power level of the memory.
 3. The system on chip of claim 1, wherein the power manager is further configured to determine whether the memory access level is equal to or higher than a preset access level threshold, and when the memory access level is equal to or higher than the preset access level threshold, the power manager is further configured to set the supply power level regarding the memory to a new supply power level that is higher than a current supply power level.
 4. The system on chip of claim 3, wherein, after the supply power level of the memory is set, the power manager is further configured to output, to the memory controller, a power increase completion signal regarding the memory.
 5. The system on chip of claim 1, wherein the power manager is further configured to determine whether the memory access level is equal to or higher than an access level threshold, and when the memory access level is not equal to or higher than the access level threshold, the power manager is further configured to set the supply power level of the memory to a new supply power level that is lower than a current supply power level.
 6. Th system on chip of claim 5, wherein the power manager is further configured to output a power decrease request signal to the memory controller before the supply power level of the memory is set to the new supply power level.
 7. The system on chip of claim 5, wherein, when the power manager sets the supply power level of the memory to the new supply power level, the memory controller comprises a delaying unit configured to delay outputting a response corresponding to an access of a master or to store the access of the master in an access queue.
 8. The system on chip of claim 5, wherein, when the power manager sets the supply power level of the memory to the new supply power level, the memory controller comprises a blocking unit configured to output a fail signal in response to an access of a master.
 9. The system on chip of claim 1, wherein the memory controller comprises a transition unit configured to inactivate a clock that is input to the memory controller, and the transition unit inactivates the clock occurring during a power transition interval in which the supply power level of the memory is changed.
 10. The system on chip of claim 1, wherein the power manager is further configured to adjust the supply power level of the memory by outputting a control signal to the memory.
 11. The system on chip of claim 1, wherein the power manager is further configured to adjust the supply power level of the memory by outputting a control signal to a power source that is configured to supply power to the memory.
 12. A method of operating a power manager comprised in a system on chip (SoC), the method comprising: receiving a memory access level indicating a frequency of accesses to a memory from a memory controller; determining whether the memory access level is equal to or higher than an access level threshold; and outputting a control signal for setting a supply power level of the memory.
 13. The method of claim 12, wherein, when the power manager determines that the memory access level is equal to or higher than the access level threshold, the outputting of the control signal comprises outputting a control signal for setting the supply power level of the memory to a new supply power level that is higher than a current supply power level, and the method further comprises outputting a power increase completion signal regarding the memory to the memory controller.
 14. The method of claim 12, wherein, when the power manager determines that the memory access level is not equal to or higher than the access level threshold during the determining, the method further comprises: outputting a power decrease request signal regarding the memory to the memory controller; and receiving an acknowledgement signal from the memory controller, and the outputting of the control signal comprises outputting a control signal for setting the supply power level of the memory to a new supply power level that is lower than a current supply power level.
 15. The method of claim 12, wherein the outputting of the control signal comprises: outputting the control signal to a power switch comprised in the memory or to a power source configured to supply power to the memory.
 16. A system on chip (SoC), comprising: a memory; a processor configured to execute instructions to control the memory; and a power manager configured to manage a supply power level of the memory, wherein, when executed by the processor, the instructions cause the system on chip to perform a process comprising: outputting, from the processor to the power manager, a memory access level indicating a frequency of accesses to the memory, and adjusting, by the power manager, the supply power level of the memory according to the memory access level.
 17. The system on chip of claim 16, wherein the process further comprises: comparing, by the power manager, the memory access level to a preset access level threshold, and setting, by the power manager, the supply power level of the memory to a new supply power level based on the comparing.
 18. The system on chip of claim 16, wherein the process further comprises: either delaying, by the processor, output of a response corresponding to an access of a master, or storing, by the processor, the access of the master in an access queue.
 19. The system on chip of claim 16, wherein the process further comprises: outputting a fail signal in response to an access of a master.
 20. The system on chip of claim 16, wherein the SoC comprises a single, integrated system with all elements directly or indirectly connected to a single substrate. 